TRAIL mutant membrane penetrating peptide alike (TMPPA) TRAIL-Mu3 enhances the antitumor effects of TRAIL in vitro and in vivo

Construction and validation of a novel tumor necrosis factor-related apoptosis-inducing ligand mutant MuR5S4-TR

AIM

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) can selectively kill tumor cells but has no significant effect on normal cells. However, the use of TRAIL is limited for resistance by more than 50% of the tumor cell lines. It's very important to develop a more efficient form of TRAIL for cancer treatment.

METHODS

The N-terminal in soluble fragments (114-281aa) of TRAIL was redesigned to construct a novel TRAIL mutant-MuR5S4-TR. The Cell Counting Kit-8 method to explore the antitumor effects. The potential mechanisms were also explored.

RESULTS

Novel TRAIL mutant with cell-penetrating peptides (CPP) like and Second mitochondria-derived activator of caspases (Smac) like structure-MuR5S4-TR was successfully constructed. The prokaryotic expression system was successfully built, and the MuR5S4-TR was purified and reconfirmed by western blot. MuR5S4-TR could enhance the antitumor effects of TRAIL in most of the cancer cell lines significantly, NCI-H460 lung cancer cell line, for instance. After MuR5S4-TR treatment, the expressions of death receptor 4 (DR4), DR5, Caspase-8, and cleaved Caspase-3 were remarkably increased, however, there was no significant difference in X-linked inhibitor of apoptosis expression.

CONCLUSION

We constructed a novel TRAIL mutant with CPP-like and Smac-like structure-MuR5S4-TR. The MuR5S4-TR showed significantly stronger antitumor effects than TRAIL in many tumor cell lines. The MuR5S4-TR showed strong antitumor effects both in vitro and in vivo. This preliminary study implies that MuR5S4-TR may be a more efficient form of TRAIL for cancer therapy.

ptARgenOM-A Flexible Vector For CRISPR/CAS9 Nonviral Delivery

Viral-mediated delivery of the CRISPR-Cas9 system is one the most commonly used techniques to modify the genome of a cell, with the aim of analyzing the function of the targeted gene product. While these approaches are rather straightforward for membrane-bound proteins, they can be laborious for intracellular proteins, given that selection of full knockout (KO) cells often requires the amplification of single-cell clones. Moreover, viral-mediated delivery systems, besides the Cas9 and gRNA, lead to the integration of unwanted genetic material, such as antibiotic resistance genes, introducing experimental biases. Here, an alternative non-viral delivery approach is presented for CRISPR/Cas9, allowing efficient and flexible selection of KO polyclonal cells. This all-in-one mammalian CRISPR-Cas9 expression vector, ptARgenOM, encodes the gRNA and the Cas9 linked to a ribosomal skipping peptide sequence followed by the enhanced green fluorescent protein and the puromycin N-acetyltransferase, allowing for transient, expression-dependent selection and enrichment of isogenic KO cells. After evaluation using more than 12 distinct targets in 6 cell lines, ptARgenOM is found to be efficient in producing KO cells, reducing the time required to obtain a polyclonal isogenic cell line by 4-6 folds. Altogether ptARgenOM provides a simple, fast, and cost-effective delivery tool for genome editing.

Recombinant protein TRAIL-Mu3 enhances the antitumor effects in pancreatic cancer cells by strengthening the apoptotic signaling pathway

Pancreatic cancer is a highly malignant type of cancer and its treatment remains a major challenge. The novel recombinant protein TNF-related apoptosis-inducing ligand (TRAIL)-Mu3 has been shown to exert stronger tumor inhibitory effects in colon cancer in vitro and in vivo compared with TRAIL. The present study investigated the antitumor effects of TRAIL-Mu3 on pancreatic cancer cells, and the possible mechanisms were further examined. Compared with TRAIL, TRAIL-Mu3 exhibited significantly higher cytotoxic effects on pancreatic cancer cell lines. The inhibitory effect of TRAIL-Mu3 on the viability of PANC-1 cells was shown to be a caspase-dependent process. The affinity of TRAIL-Mu3 to PANC-1 cell membranes was significantly enhanced compared with TRAIL. In addition, TRAIL-Mu3 upregulated death receptor (DR) expression in PANC-1 cells and promoted the redistribution of DR5 in lipid rafts. Western blotting results demonstrated that TRAIL-Mu3 activated the caspase cascade in a faster and more efficient manner compared with TRAIL in PANC-1 cells. Therefore, TRAIL-Mu3 enhanced the antitumor effects in pancreatic cancer cells by strengthening the apoptotic signaling pathway. The present study indicated the potential of TRAIL-Mu3 for the treatment of pancreatic cancer.

Overview of the oncogenic signaling pathways in colorectal cancer: Mechanistic insights

Colorectal cancer is a multifaceted disease which is therapeutically challenging. Based on insights gleaned from almost a quarter century of research, it is obvious that deregulation of spatio-temporally controlled signaling pathways play instrumental role in development and progression of colorectal cancer. High-throughput technologies have helped to develop a sharper and broader understanding of the wide ranging signal transduction cascades which also contribute to development of drug resistance, loss of apoptosis and, ultimately, of metastasis. In this review, we have set the spotlight on role of JAK/STAT, TGF/SMAD, Notch, WNT/β-Catenin, SHH/GLI and p53 pathways in the development and progression of colorectal cancer. We have also highlighted recent reports on TRAIL-mediated pathways and molecularly distinct voltage-gated sodium channels in colorectal cancer.